Computer system, a telecommunication device and a telecommunication network

ABSTRACT

A telecommunication network  20  configures a telecommunication device  11  and makes and controls communication connections between telecommunication devices. The telecommunication network  20  is configured such that, in use, on initiation of the telecommunication device  11,  such as an Internet Protocol telephone or video telephone, a telecommunication device identifier to identify the telecommunication device  11  is output to a computer system or provisioning server  41  via the Internet  10.  The computer system  41  receives the telecommunication device identifier and, in response, outputs to the telecommunication device  11,  via the Internet  10,  an indication of a telecommunication device control system or PBX  12  for use by the telecommunication device  11.  The telecommunication device control system  12  is subsequently usable by the telecommunication device  11  to make and control communication connections between the telecommunication device  11  and other telecommunication devices.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Patent Application No. 61/705,990, filed on Sep. 26, 2012. This application also claims the benefit of United Kingdom Patent Application No. GB1217211.0, filed on Sep. 26, 2012. The disclosures of these applications are hereby incorporated by reference herein in their entireties and made a part of the present disclosure.

TECHNICAL FIELD

The present invention relates generally to a computer system, a telecommunication device and a telecommunication network. Embodiments of the invention relate to initial configuration of a telecommunication device such as an Internet Protocol (IP) telephone or IP video telephone.

BACKGROUND

Calls made by telephones and video telephones are controlled by a call-control system or telecommunication device control system that is usually referred to as a PBX. PBX stands for private branch exchange. While the control systems used by modern VOIP (voice over IP) telephone systems do not exchange anything the term PBX is still commonly used to describe the controllers that have the same core functionality of PBXs used in public switched telephone networks where the term originated.

Modern VOIP telephones need to know the PBX that they are to use to control calls to and from them. There are several known arrangements for providing configuration information to such known IP telephony devices. That is to say, to provide the address or an identifier of the call-control system or telecommunication device control system (PBX) for the IP telephony network. Provisioning of IP telephones falls broadly into three categories, which are described below with reference to FIGS. 1 to 3.

FIG. 1 illustrates a known IP telephone 11 on a telecommunication network which is manually configured with the IP address of the PBX 12 in order to establish the call-control connection 13 across the Internet 10. In the simple arrangement of FIG. 1 the IP telephone is manually told the IP address of the PBX, for example, by a user making an appropriate input using the telephone keypad or the telephone's web interface.

This mechanism allows no flexibility in changing that IP address at a later time without manually reprovisioning all of an organisation's IP telephones, it allows very little flexibility about the location of the PBX relative to the telephone and, furthermore, before first using the telephone a user must make this manual entry, which is often overly complex for a typical end-user to perform.

FIG. 2 illustrates a known IP telephone 11 which is on a network where a dynamic host configuration protocol (DHCP) server 21 provides the IP address of the PBX 12 to the IP telephone at boot time or on start-up via the Internet 10. In this arrangement, the DHCP server informs all the IP telephones on a particular local-area network (LAN) of the IP address of the PBX. To emphasise, the DHCP server is located on the same LAN as the IP telephone being configured. This has some advantages of the arrangement of FIG. 1 in that it is easy to deploy plural IP telephones on a single site, but does not work well for multiple sites or for individual IP telephones, particularly where the IP telephone is being connected to a network not managed by the owner of the IP telephone. It allows some flexibility about the geographical location of the PBX relative to the telephone through techniques such as geographically-aware DNS servers, but it is still complex and cumbersome for a typical end-user to configure.

FIG. 3 illustrates an IP telephone 11 on a telecommunication network which is manually configured with the domain name system (DNS) name of the PBX 12 which it resolves into an IP address using DNS server 31. The arrangement of FIG. 3 uses a DNS server to provide a single level of indirection (means to look up an identifier or pointer to get to the desired destination). The IP telephone is provided with the DNS name of the PBX and the IP telephone then locates a DNS server from its network configuration and queries the DNS server for the address of the PBX. This is achieved by a DHCP server or another device on the local network (not shown in FIG. 3) providing the necessary configuration information to the IP telephone as it boots to allow it to discover the IP address of the PBX. Geolocation DNS services may be used to provide a different PBX address based on geographical knowledge about the IP address of the telephone. This mechanism works for simple systems where there is only one PBX or a group of PBXs all belonging to the same organisation and which can all accept connections from a telephone belonging to that organisation. In other words, it works well for networks that are administered by the same organisation that own the PBX, it provides for operation of an IP telephone without pre-configuration, and is easy for an end-user to deploy, but it is not possible to use on an arbitrary network such as a public or home Internet connection which is typically where ease of deployment is particularly advantageous.

SUMMARY

The inventors of the arrangement described below are the first to appreciate that the desirable zero-configuration for the end-user to deploy an IP telephone as received from the manufacturer without them having to key in any configuration information, regardless of the nature of the network on which the telephone will be deployed is met by providing a provisioning server or particular computer system connected to the IP telephone via the Internet. Embodiments of the provisioning server or computer system receive from the IP telephone or video telephone, via the Internet, a telecommunication device identifier to identify the telecommunication device. In response, the provisioning server outputs to the telecommunication device, via the Internet, an indication of a telecommunication device control system or PBX for use by the telecommunication device. In this way, the provisioning server may be owned and managed by a different organisation to the customer or user of the telephone in order to provide parameterless provisioning for the telephone regardless of the customer or user.

Embodiments of the computer system provide configuration information to an IP enabled telephone. A newly connected telephone or video telephone device may fetch configuration information from a device or devices on the Internet to enable it to establish communications with an Internet telephony control system or PBX.

Embodiments of the provisioning server or device provide to an IP telephone or video telephone information about its PBX and other supporting media systems based on the identity of the telephone, and in some examples, its geographical location, and a preconfigured association between that telephone, the owning organisation and the PBX belonging to that organisation.

The invention in its various aspects is defined in the independent claims below to which reference should now be made. Advantageous features are set forth in the dependent claims.

Arrangements are described in more detail below and take the form of a telecommunication network that configures a telecommunication device and makes and controls communication connections between telecommunication devices. The telecommunication network is configured such that, in use, on initiation of the telecommunication device, such as an Internet Protocol telephone or video telephone, a telecommunication device identifier to identify the telecommunication device is output to a computer system or provisioning server via the Internet. The computer system receives the telecommunication device identifier and, in response, outputs to the telecommunication device, via the Internet, an indication of a telecommunication device control system or PBX for use by the telecommunication device. The telecommunication device control system is subsequently usable by the telecommunication device to make and control communication connections between the telecommunication device and other telecommunication devices.

In an aspect of the present invention, there is provided a computer system for providing to a telecommunication device an indication of a telecommunication device control system for use by the telecommunication device, the computer system being configured to connect to the Internet and being further configured to: receive from a telecommunication device, via the Internet, a telecommunication device identifier to identify the telecommunication device; and output to the telecommunication device, via the Internet, in response to the telecommunication device identifier: an indication of a telecommunication device control system for use by the telecommunication device; or an indication of a gateway usable to reach the telecommunication device control system for use by the telecommunication device; or an indication of another computer system for providing to the telecommunication device an indication of a telecommunication device control system for use by the telecommunication device.

In another aspect of the present invention, there is provided a telecommunication device for receiving an indication of a telecommunication device control system for use by the telecommunication device, the telecommunication device being configured to connect to the Internet and being further configured to on initiation: output to a computer system, via the Internet, a telecommunication device identifier to identify the telecommunication device; and receive from the computer system, via the Internet, in response to the output of the telecommunication device identifier: an indication of a telecommunication device control system for use by the telecommunication device; or an indication of a gateway usable to reach the telecommunication device control system for use by the telecommunication device; or an indication of another computer system for providing to the telecommunication device an indication of a telecommunication device control system for use by the telecommunication device.

In a yet further aspect of the present invention, there is provided a telecommunication network for configuring a telecommunication device and making and controlling communication connections between telecommunication devices, the telecommunication network comprising: a telecommunication device, a computer system for providing to the telecommunication device an indication of a telecommunication device control system for use by the telecommunication device, and a telecommunication device control system connected via the Internet; the telecommunication device being configured to, on initiation: output to the computer system, via the Internet, a telecommunication device identifier to identify the telecommunication device; and receive from the computer system, via the Internet, in response to the output of the telecommunication device identifier: an indication of a telecommunication device control system for use by the telecommunication device; or an indication of a gateway usable to reach the telecommunication device control system for use by the telecommunication device; or an indication of another computer system for providing to the telecommunication device an indication of a telecommunication device control system for use by the telecommunication device; the computer system being configured to: receive from the telecommunication device, via the Internet, the telecommunication device identifier to identify the telecommunication device; and output to the telecommunication device, via the Internet, in response to the telecommunication device identifier: an indication of a telecommunication device control system for use by the telecommunication device; or an indication of a gateway usable to reach the telecommunication device control system for use by the telecommunication device; or an indication of another computer system for providing to the telecommunication device an indication of a telecommunication device control system for use by the telecommunication device; and the telecommunication device control system being configured to make and control communication connections between the telecommunication device and other telecommunication devices; the telecommunication network being configured such that, in use, on initiation of the telecommunication device: a telecommunication device identifier to identify the telecommunication device is output to the computer system via the Internet; the computer system receives the telecommunication device identifier and, in response, via the Internet: an indication of a telecommunication device control system for use by the telecommunication device, or an indication of a gateway usable to reach the telecommunication device control system for use by the telecommunication device is output to the telecommunication device, such that the telecommunication device control system is subsequently usable to make and control communication connections between the telecommunication device and other telecommunication devices; or an indication of another computer system for providing to the telecommunication device an indication of a telecommunication device control system for use by the telecommunication device is output to the telecommunication device.

In another aspect of the present invention, there is provided a computerized method for providing to a telecommunication device an indication of a telecommunication device control system for use by the telecommunication device, the computerized method comprising: a computer system receiving from a telecommunication device, via the Internet, a telecommunication device identifier to identify the telecommunication device; and the computer system outputting to the telecommunication device, via the Internet, in response to the telecommunication device identifier: an indication of a telecommunication device control system for use by the telecommunication device; or an indication of a gateway usable to reach the telecommunication device control system for use by the telecommunication device; or an indication of another computer system for providing to the telecommunication device an indication of a telecommunication device control system for use by the telecommunication device.

In a yet further aspect of the present invention, there is provided a telecommunication method for receiving an indication of a telecommunication device control system for use by a telecommunication device, the telecommunication method comprising: outputting to a computer system, via the Internet, a telecommunication device identifier to identify the telecommunication device; and receiving from the computer system, via the Internet, in response to the output of the telecommunication device identifier: an indication of a telecommunication device control system for use by the telecommunication device; or an indication of a gateway usable to reach the telecommunication device control system for use by the telecommunication device; or an indication of another computer system for providing to the telecommunication device an indication of a telecommunication device control system for use by the telecommunication device.

In a still further aspect of the present invention, there is provided a method of operating a telecommunication network for configuring a telecommunication device and making and controlling communication connections between telecommunication devices, the method comprising: on initiation of a telecommunication device, the telecommunication device outputting to a computer system, via the Internet, a telecommunication device identifier to identify the telecommunication device; the computer system receiving from the telecommunication device, via the Internet, the telecommunication device identifier to identify the telecommunication device; the computer system outputting to the telecommunication device, via the Internet, in response to the telecommunication device identifier: an indication of a telecommunication device control system for use by the telecommunication device; or an indication of a gateway usable to reach the telecommunication device control system for use by the telecommunication device; or an indication of another computer system for providing to the telecommunication device an indication of a telecommunication device control system for use by the telecommunication device; and the telecommunication device receiving from the computer system, via the Internet, in response to the output of the telecommunication device identifier: an indication of a telecommunication device control system for use by the telecommunication device; or an indication of a gateway usable to reach the telecommunication device control system for use by the telecommunication device; or an indication of another computer system for providing to the telecommunication device an indication of a telecommunication device control system for use by the telecommunication device; wherein the telecommunication device control system makes and controls communication connections between the telecommunication device and other telecommunication devices.

In a yet further aspect of the present invention, there is provided a computer-readable medium containing a set of instructions that causes a computer to perform a method for providing to a telecommunication device an indication of a telecommunication device control system for use by the telecommunication device, the method comprising: outputting to a telecommunication device, via the Internet, in response to receiving a telecommunication device identifier from a telecommunication device, via the Internet: an indication of a telecommunication device control system for use by the telecommunication device; or an indication of a gateway usable to reach the telecommunication device control system for use by the telecommunication device; or an indication of another computer system for providing to the telecommunication device an indication of a telecommunication device control system for use by the telecommunication device.

In another aspect of the present invention, there is provided a computer-readable medium containing a set of instructions that causes a telecommunication device to perform a method of receiving an indication of a telecommunication device control system for use by the telecommunication device, the method comprising: outputting to a computer system, via the Internet, a telecommunication device identifier to identify the telecommunication device; and, in response, receiving from the computer system, via the Internet: an indication of a telecommunication device control system for use by the telecommunication device; or an indication of a gateway usable to reach the telecommunication device control system for use by the telecommunication device; or an indication of another computer system for providing to the telecommunication device an indication of a telecommunication device control system for use by the telecommunication device. The computer-readable medium may be a storage device such as a solid-state memory, hard-disk drive, CD-ROM or DVD-ROM. The methods described may be carried out by a computer program.

The computer system may be a single computer or a plurality of computers on a network. The telecommunication device control system may be a single computer, a plurality of computers on a network or a bespoke hardware configuration.

Advantageous features are set-out below any may be included in any of the aspects of the present invention set-out above.

The telecommunication device may comprise an Internet Protocol telephone or video telephone.

The telecommunication device control system may comprise a PBX.

The telecommunication device identifier may comprise an indication of the location of the telecommunication device. The indication of the location of the telecommunication device may be used by the computer system to select the indication of a telecommunication device control system for use by the telecommunication device to output, the indication of a gateway usable to reach the telecommunication device control system for use by the telecommunication device; or the indication of another computer system for providing to the telecommunication device an indication of a telecommunication device control system for use by the telecommunication device.

The telecommunication device identifier may comprise one or more from a list comprising: a hardware identifier, such as a MAC address or serial number, and optionally a password; a user-supplied username, and optionally a password; an identifier provided by a smart card or a biometric reader, and optionally a password.

The indication of a telecommunication device control system for use by the telecommunication device, the indication of a gateway usable to reach the telecommunication device control system for use by the telecommunication device and/or the indication of another computer system for providing to the telecommunication device an indication of a telecommunication device control system for use by the telecommunication device may comprise an Internet Protocol address.

The indication of a telecommunication device control system for use by the telecommunication device, the indication of a gateway usable to reach the telecommunication device control system for use by the telecommunication device and/or the indication of another computer system for providing to the telecommunication device an indication of a telecommunication device control system for use by the telecommunication device may comprise a domain name system name.

The computer system may be configured to verify the telecommunication device identifier. The computer system may be configured to generate an indication that the telecommunication device identifier is not recognised if the telecommunication device identifier is not recognised following the verification.

The computer system may be configured to generate a token to identify a user of the telecommunication device. The token may be human-readable. The token may comprise one or more check digits. The computer system may be configured to request the user to enter the token. The computer system may be configured to provide an indication to the telecommunication device for a user of the telecommunication device to enter the token following the generation of an indication that the telecommunication device identifier is not recognised. The computer system may be configured to receive the token from the telecommunication device. The computer system may be configured to bind with the telecommunication device identifier following receipt of the token and the telecommunication device identifier from the telecommunication device: the user's account; or the indication of the telecommunication device control system; or the indication of the gateway usable to reach the telecommunication device control system. The telecommunication device may be configured to receive an indication that the telecommunication device identifier is not recognised by the computer system. The telecommunication device may be configured to request a user to enter a token following receipt of an indication that the telecommunication device identifier is not recognised by the computer system. The telecommunication device may be configured to output the token to the computer system after the token has been entered. The computer system may be configured to receive the token from the telecommunication device.

The telecommunication device may be further configured such that on receiving an indication of another computer system for providing to the telecommunication device an indication of a telecommunication device control system for use by the telecommunication device, the telecommunication device outputs to the another computer system, via the Internet, a telecommunication device identifier to identify the telecommunication device.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described in more detail, by way of example, with reference to the accompanying drawings, in which:

FIGS. 1, 2 and 3 (prior art) are schematic diagrams of known telecommunication networks;

FIG. 4 is a schematic diagram of a telecommunication device, computer system and telecommunication network embodying an aspect of the present invention;

FIG. 5 is a flow diagram illustrating the operation of the telecommunication network of FIG. 4; and

FIG. 6 is a schematic diagram of a telecommunication device, computer system and telecommunication network of another embodiment of an aspect of the present invention.

DETAILED DESCRIPTION

Embodiments of the invention will now be described with reference first to FIGS. 4 and 5.

FIG. 4 illustrates a telecommunication network 20 for configuring a telecommunication device in the form of an IP telephone 11 and making and controlling communication connections between telecommunication devices such as other IP telephones (not shown). The telecommunication network includes the telecommunication device or IP telephone 11, a computer system for providing to the telecommunication device an indication of a telecommunication device control system for use by the telecommunication device in the form of provisioning server (PS) 41, and a telecommunication device control system in the form of PBX 12. The telecommunication device control system makes and controls communication connections between the IP telephone 11 and other telecommunication devices or IP telephones. All of these components are connected via the Internet 10.

The provisioning server 41 is created on the public Internet. Typically, it is not run by the organisation or company owning the IP telephone 11 or the IP PBX 12. They may be run by the manufacturer of the IP telephones, or by an independent organisation. They are trusted by the IP telephones to provide the necessary information to reach the PBX or a gateway belonging to the company that owns the IP telephone. The IP telephone 11 locates a provisioning server 41 using any of the methods described below such as resolving a well-known name using a DNS server 31. The provisioning server then provides information to the telephone in order for it to connect to the correct PBX 12.

In summary, as illustrated in the flow diagram 100 of FIG. 5 and with reference to FIG. 4, the telecommunication device or IP telephone 11, on initiation, during booting or start-up, outputs to the computer system or provisioning server 41, via the Internet 10, a telecommunication device identifier to identify the telecommunication device (step 102 of FIG. 5). The computer system or provisioning server receives from the telecommunication device or IP telephone, via the Internet, the telecommunication device identifier (step 104 of FIG. 5). In response, it outputs to the telecommunication device or IP telephone, via the Internet, an indication of a telecommunication device control system or PBX for use by the telecommunication device (step 106 of FIG. 5). The indication of the PBX is received from the computer system or provisioning server at the IP telephone (step 108 of FIG. 5). In this way, the telecommunication device control system or PBX is subsequently usable to make and control communication connections between the telecommunication device or IP telephone and other telecommunication devices or IP telephones.

The provisioning server may be a single computer or a plurality of computers on a network. The PBX may also be a single computer or a plurality of computers on a network or it may be implemented in dedicated hardware.

In more detail, the start-up or initiation procedure of the IP telephone 11 or telecommunication device is as follows.

When initially plugged in to an Ethernet socket, the IP telephony device 11 obtains standard IP configuration from the local network to which it is connected, for instance using DHCP or IPv6 RS messages.

The IP telephone 11 then discovers the IP address of a provisioning server 41. This may be done using several methods as set-out below.

For example, standard IP configuration may provide the location of a DNS service. DNS is used to resolve a well-known name to an IP address. Alternatively, the same DNS mechanism may be used, but the DNS server may use the IP address of the IP telephone 11 to enable it to respond with the geographically nearest provisioning server. Alternatively, the DNS server may be given an Anycast address and may be configured to reply with the geographically nearest provisioning server. Anycast is a network addressing and routing system in which data is routed to the topologically nearest node of a group identified by the same address. Alternatively, the provisioning server may be given an Anycast address and the IP telephone may be preconfigured to know this address.

The IP telephone 11 then establishes a communication connection with the provisioning server 41 using this IP address. Communications via this communication connection may be encrypted using public-key cryptography in order to protect the identity of the IP telephone, the user and the IP PBX 12.

The IP telephone then supplies identification information in the form of a telecommunication device identifier to identify the telecommunication device to the provisioning 41 server. This may take several forms, such as: a hardware identifier, such as a Media Access Control (MAC) address, digital certificate or serial number and optionally a password; or a software identifier such as a user-supplied username or email address and optionally a password, or an identifier (and optionally a password) provided by a smart card or a biometric reader.

The provisioning server 41 then looks up the identification information supplied by the user to determine the possible addresses of the PBX associated with that device or user.

If the request from the IP telephone 11 is authenticated then it checks that the authentication matches. This may be carried out locally by the provisioning server, or it may delegate that operation to the PBX or another device by establishing a communication connection and requesting authentication. In one possible arrangement, the look-up is authenticated using a digital certificate and the provisioning server 41 checks that the certificate is valid.

As mentioned above, when the IP telephone 11 first contacts the provisioning server 41, it presents either a software identification (ID) (for example, username or email address) or a hardware identification (ID) (for example, a MAC address or a digital certificate). The provisioning server is preconfigured with the ID and the associated PBX 12 for it to respond by a user typing in the relevant information. In the case of a hardware ID, this manual data entry is prone to user error because, for example, a MAC address is 12 hexadecimal digits and has no check digit or checksum thus it is easy for a user to make a data entry error by, for example, typing 8 instead of B or 0 instead of C.

An arrangement to address this problem is described below.

In this arrangement, an administrator configures a user account on the provisioning server 41 and the provisioning server generates a token which identifies a user of a telecommunication device or IP telephone. In this example, the token is a human-readable (for example, it contains only decimal digits) and long (for example, it contains 8 or more digits, or 12 or more digits, but preferably 12 digits). The token includes one or more check digits to identify whether it is a valid token. The token is sent to the user by secure means (for example, by internal email or post).

With this arrangement, when the IP telephone 11 boots or is initiated and makes a request using its hardware ID, the provisioning server 41 verifies or validates the request and if it does not recognise the request it responds with an indication accordingly to the IP telephone that it does not know the ID. The IP telephone then indicates to the user or makes a request to the user (typically, on its display) to enter the token. Once the user has entered the token typically using the IP telephone's keypad, the telephone sends the token and the hardware ID to the provisioning server which receives the token, validates the token, identifies the user, and then automatically binds or links that hardware ID with that user for future requests by binding the telecommunication device identifier to the user account or PBX for which the token was issued. Alternatively, the token may be time-limited and/or single-use only (for the first configuration only).

Once the provisioning server 41 has received a valid ID or token, it returns to the requesting device (IP telephone 11) the IP address of the target PBX or a gateway which may be used to reach the target PBX. Alternatively, the provisioning server may return the domain name system name of the target PBX or a gateway usable to reach the target PBX. In other words, it outputs to the telecommunication device or IP telephone, via the Internet, an indication of a telecommunication device control system or PBX for use by the telecommunication device or an indication of a gateway to reach them or an indication of another provisioning server to which the device should repeat the request as described below with reference to the embodiment of FIG. 6.

The provisioning server 41 may be provided with geographical or location information about the requesting IP telephone 11. This may be obtained using several methods, such as: geographical knowledge by the provisioning server 41 of public IP address allocations (that is to say, it uses the IP address of the IP telephone to determine the telephone's location); latitude/longitude provided in the request from the IP telephone (which may be retrieved by a global positioning system (GPS) receiver in the device, for example); or indications or identities (IDs) of local wireless networks or cell towers (mobile telecommunications masts) within range of the requesting device as provided by the device in the request.

This extra information may be used by the provisioning server 41 to allow the requesting IP telephone 11 to be directed to the nearest entry-point into the target PBX's network. This may be a local connection to a distributed PBX, or may be a local gateway to the network of the customer.

IP telephone 11 may also verify the trust of the provisioning server 41 in order to avoid unexpected connection to an attackers gateway which could be used to intercept calls. This trust is typically achieved using public key cryptography.

Typically, an IP telephone 11 encrypts the channel over which provisioning information is carried. This prevents leakage of information such as the username of the connecting telephone. Leakage of this information could reveal the association between a person and a company or organisation. This trust may be established using a mechanism such as secure sockets layer (SSL) utilising the public key cryptography used to identify the provisioning server 41 as a trust mechanism.

FIG. 6 illustrates another embodiment of the present invention. It is similar in many respects to the embodiment of FIG. 4 and like features have been given like reference numerals.

In the embodiment of FIG. 6, like the arrangement of FIG. 4, the IP telephone 11 locates a provisioning server 41 using any of the methods described above such as resolving a well-known name using a DNS server 31. In contrast to the arrangement of FIG. 4, in the arrangement of FIG. 6, the provisioning server 41 then redirects the provisioning process to another provisioning server 51 which provides information to the IP telephone in order for it to connect to the correct PBX 12. Thus, an indication of another computer system for providing to the telecommunication device an indication of a telecommunication device control system for use by the telecommunication device is provided to the IP telephone.

In other words, in the example of FIG. 6, the provisioning server 41 may choose to delegate the provisioning process to a sub-provisioning server (SPS) 51 to which it is in communication connection via the Internet 10. In this case, the initial provisioning server 41 instructs the IP telephone 11 to disconnect from the initial provisioning server then instead connect to the sub-provisioning server. This process may be repeated. In this way, instead of sending out an indication of a telecommunications device control system or gateway usable to reach the telecommunications device control system being output in response to a provisioning server receiving a telecommunication device identifier, an identifier or indicator of a delegated provisioning server or system may be output to the IP telephone 11. When the telephone receives the identifier of a delegated provisioning server or system, it restarts the provisioning process described above with this new system. Sub-provisioning servers may themselves each delegate to another sub-provisioning server. The ownership of the sub-provisioning servers may differ from the ownership of the initial provisioning server. A sub-provisioning server may be owned by the organisation that owns an associated PBX or group of PBXs.

The system described has an initial provisioning server 41 that contains a database associating the identity of the IP telephone 11 with the address of either the PBX 12 to which the telephone needs to connect, or the address of a sub-provisioning server 51.

As in the arrangement of FIG. 4, in the arrangement of FIG. 6, the telephone 11 is identified by a hardware identifier (MAC address or serial number) or a username or a digital certificate. In the case of a hardware identifier, a company or organisation may register their hardware identifiers with a central configuration database, providing the PBX or SPS address to configure the provisioning server.

Interception attacks may be prevented by only allowing a hardware identifier to be registered once without intervention from a human administrator. Hardware identifiers may also be registered and associated with a customer account by the manufacturer or distributor of the IP telephone 11.

In the case of a username as an identifier for an IP telephone 11, the name may be of a fixed format such as an email address. The name may be pattern matched (such as choosing the domain part of an email address) to identify the PBX or SPS address.

In the case of a digital certificate as an identifier for an IP telephone 11, the Common Name or some other known identifier in the certificate may be used in a similar fashion to the username case described above.

If more than one PBX 12 or SPS 51 is registered with a PS 41 or SPS 51 for a particular telephone identity, then the PS or SPS may decide based on geographical location information contained within the configuration request as to which PBX or SPS is returned in the configuration response.

An IP telephone 11 utilising the provisioning features described herein, which was owned by managed offices could offer temporary connection to a corporate PBX via that telephone as part of an office rental in other word a public hot-desking arrangement.

For example, an employee of a company or organisation may rent an office for a short period, that rental including use of a telephone 11 using the provisioning mechanism described above. The employee may then connect to the company's telecommunications system by identifying themselves using a hardware token such as a smart card or credentials such as a username and password. That telephone is then directed to connect to the company's telephone system and takes on the characteristics assigned by that company for the duration of the users residence in the rented office.

Embodiments of the present invention have been described. It will be appreciated that variations and modifications may be made to the described embodiments within the scope of the present invention. For example, while embodiments have been described with reference to a telecommunication device in the form of an IP telephone, the telecommunication device may be an IP video telephone or videophone. 

1-55. (canceled)
 56. A computer system for providing to a telecommunication device an indication of a telecommunication device control system for use by the telecommunication device, the computer system being configured to connect to the Internet, the computer system comprising: at least one hardware processor configured to: receive from a telecommunication device, via the Internet, a telecommunication device identifier to identify the telecommunication device; and output to the telecommunication device, via the Internet, in response to the telecommunication device identifier: an indication of a telecommunication device control system for use by the telecommunication device; or an indication of a gateway usable to reach the telecommunication device control system for use by the telecommunication device; or an indication of another computer system for providing to the telecommunication device an indication of a telecommunication device control system for use by the telecommunication device, wherein the at least one hardware processor is further configured to: verify the telecommunication device identifier; generate an indication that the telecommunication device identifier is not recognised if the telecommunication device identifier is not recognised following the verification; generate a token to identify a user of the telecommunication device; request the user to enter the token; provide an indication to the telecommunication device for a user of the telecommunication device to enter the token following the generation of an indication that the telecommunication device identifier is not recognized; receive the token from the telecommunication device; and following receipt of the token and the telecommunication device identifier from the telecommunication device, bind with the telecommunication device identifier one of: the user's account; or the indication of the telecommunication device control system; or the indication of the gateway usable to reach the telecommunication device control system.
 57. A computer system according to claim 56, wherein the telecommunication device comprises an Internet Protocol telephone or video telephone.
 58. A computer system according to claim 56, wherein the telecommunication device control system comprises a private branch exchange (PBX).
 59. A computer system according to claim 56, wherein the telecommunication device identifier comprises an indication of the location of the telecommunication device.
 60. A computer system according to claim 59, wherein the at least one hardware processor is further configured to use the indication of the location of the telecommunication device to select the indication of a telecommunication device control system for use by the telecommunication device to output, the indication of a gateway usable to reach the telecommunication device control system for use by the telecommunication device; or the indication of another computer system for providing to the telecommunication device an indication of a telecommunication device control system for use by the telecommunication device.
 61. A computer system according to claim 56, wherein the telecommunication device identifier comprises one or more from a list comprising: a hardware identifier, such as a MAC address or serial number, and optionally a password; a user-supplied username, and optionally a password; an identifier provided by a smart card or a biometric reader, and optionally a password.
 62. A computer system according to claim 56, wherein the indication of a telecommunication device control system for use by the telecommunication device, the indication of a gateway usable to reach the telecommunication device control system for use by the telecommunication device and/or the indication of another computer system for providing to the telecommunication device an indication of a telecommunication device control system for use by the telecommunication device comprises an Internet Protocol address.
 63. A computer system according to claim 56, wherein the indication of a telecommunication device control system for use by the telecommunication device, the indication of a gateway usable to reach the telecommunication device control system for use by the telecommunication device and/or the indication of another computer system for providing to the telecommunication device an indication of a telecommunication device control system for use by the telecommunication device comprises a domain name system name.
 64. A computer system according to claim 56, wherein the token is human-readable.
 65. A computer system according to claim 56, wherein the token comprises one or more check digits.
 66. A computer system for providing to a telecommunication device an indication of a telecommunication device control system for use by the telecommunication device, the computer system being configured to connect to the Internet, the computer system comprising: at least one hardware processor configured to: receive from a telecommunication device, via the Internet, a telecommunication device identifier to identify the telecommunication device; and output to the telecommunication device, via the Internet, in response to the telecommunication device identifier: an indication of a telecommunication device control system for use by the telecommunication device; or an indication of a gateway usable to reach the telecommunication device control system for use by the telecommunication device; or an indication of another computer system for providing to the telecommunication device an indication of a telecommunication device control system for use by the telecommunication device, wherein the telecommunication device identifier comprises an indication of the location of the telecommunication device, and wherein the at least one hardware processor is further configured to use the indication of the location of the telecommunication device to select the indication of a telecommunication device control system for use by the telecommunication device to output, the indication of a gateway usable to reach the telecommunication device control system for use by the telecommunication device; or the indication of another computer system for providing to the telecommunication device an indication of a telecommunication device control system for use by the telecommunication device.
 67. A telecommunication device for receiving an indication of a telecommunication device control system for use by the telecommunication device, the telecommunication device being configured to connect to the Internet, the telecommunication device comprising: at least one hardware processor configured to on initiation: output to a computer system, via the Internet, a telecommunication device identifier to identify the telecommunication device; and receive from the computer system, via the Internet, in response to the output of the telecommunication device identifier: an indication of a telecommunication device control system for use by the telecommunication device; or an indication of a gateway usable to reach the telecommunication device control system for use by the telecommunication device; or an indication of another computer system for providing to the telecommunication device an indication of a telecommunication device control system for use by the telecommunication device, wherein the telecommunication device identifier comprises an indication of the location of the telecommunication device, and wherein the indication of the location of the telecommunication device is used by the computer system to select the indication of the telecommunication device control system for use by the telecommunication device, the indication of a gateway usable to reach the telecommunication device control system for use by the telecommunication device; or the indication of another computer system for providing to the telecommunication device the indication of the telecommunication device control system for use by the telecommunication device to output. 